Webster’s Revised Unabridged Dictionary · 1913
Clapper
Clap′per (klăp′pẽr), n. 1. A person who claps.
2. That which strikes or claps, as the tongue of a bell, or the piece of wood that strikes a mill hopper, etc. See Illust. of Bell.
Clapper rail (Zoöl.), an Americam species of rail (Rallus scepitans).
Clap′per, n. [F. clapier.] A rabbit burrow. [Obs.]